1. Field of the Invention
The present invention relates to an endoscope device and a control method for the same, and more specifically, an endoscope device to be used for observation of deep digestive tracts such as the small intestine and the colon, and a control method for the same.
2. Description of the Related Art
When an insertion portion of an endoscope is inserted in a deep digestive tract such as the small intestine, if the insertion portion is only pushed and inserted, it is difficult to transmit the pushing force to the distal end of the insertion portion due to complicated bends of the intestinal tract, and insertion to a deep portion is difficult. For example, when the insertion portion unnecessarily bends or warps, it becomes impossible to insert the insertion portion to a deeper side. Therefore, a method for preventing unnecessary bending and warping of the insertion portion of an endoscope by guiding the insertion portion by an insertion guide that is covered on the insertion portion and inserted in the body cavity has been proposed.
For example, JP-A-51-11689 and JP-A-11-290263 describe endoscope devices provided with a first balloon on the distal end of the insertion portion of the endoscope and a second balloon on the distal end of an insertion guide (referred to as overtube or sliding tube, also). The first balloon and the second balloon can fix the insertion portion and the insertion guide in an intestinal tract such as the small intestine by being expanded. Therefore, by alternately inserting the insertion portion and the insertion guide while repeating expansion and contraction of the first balloon and the second balloon, the insertion portion can be inserted to a deep portion of a complicatedly bent intestinal tract such as the small intestine.
However, the endoscope devices of JP-A-51-11689 and JP-A-11-290263 have a possibility that when the two balloons are expanded and the insertion portion and the insertion guide are pushed or pulled, the balloons pressurize the intestinal wall and impose a heavy burden on the intestinal tract. Therefore, the friction resistances between the balloons being expanded and the intestinal tract are important, however, neither of JP-A-51-11689 and JP-A-11-290263 disclose this.